This invention relates to a reciprocation apparatus, and more particularly to a guide assembly for a reciprocation apparatus.
In the making of metal cans, such as aluminum cans of the type typically used for beverages, it is common practice to form the bodies of the cans from pre-drawn cup-shaped blanks in a body making apparatus. The cup-shaped blanks are transformed into can bodies by striking the blanks with a punch ram and forcing them through a series of progressive dies that, in essence, stretch and elongate the sidewalls of the blanks.
Typically, the can body making apparatus includes a conventional ram guide to guide the ram as it reciprocates relative to the frame of the apparatus. Known ram guides include lubricated bronze or brass bushings, rollers and hydrostatic fluid bearings. Applications that use lubricated bronze or brass typically require a constant supply of lubrication to avoid structural damage from excessive frictional heat. If the fluid supply is interrupted for whatever reason, expensive structural failure may result that will require significant down time to replace the damaged parts. In addition, replacing the bronze or brass contact surfaces can periodically require removal of the entire guide assembly to access the brass or bronze contact sleeves.
In another example, U.S. Pat. No. 4,976,131, the entire disclosure which is herein incorporated by reference, discloses a hydrostatic fluid bearing ram guide using high pressure liquid to reduce wear and misalignment of the ram. However, hydrostatic bearings of this nature require a high-pressure source that adds to capital expenditure and operating cost. The need for additional expensive parts (e.g., pump and motor, etc.) will increase the acquisition cost of the can body making apparatus. In addition, hydrostatic bearings have a relatively high energy consumption requirement to maintain the high-pressure fluid source during use. Hydrostatic bearings further require a complex fluid guidance system including opposing pockets or orifices to direct fluid to opposing surfaces of the ram. These pockets or orifices are prone to obstruction by system impurities, thereby causing system failure due to misalignment of the ram and/or excessive frictional heat.
U.S. Pat. No. 3,696,657, the entire disclosure which is herein incorporated by reference, discloses another conventional ram guide including rollers that follow inclined edge surfaces to guide the ram along a predetermined linear path. However, roller guides have a relatively short useful life due to excessive wear between the rollers and edge surfaces. Requiring maintenance and/or replacement of the rollers can also be expensive since the support mechanism must be lifted or removed to service the rollers. In addition, roller guides may require lubrication by fluid that cannot be recovered, thereby constantly requiring additional expense for providing fresh fluid and disposing used fluid.
Accordingly, it is an object of the present invention to address and obviate problems and shortcomings of conventional ram guides. More particularly, it is an object of the present invention to provide a guide assembly with a contact member formed of a material for increased part life.
It is a further object of the present invention to decrease heat generated and system power requirements for a reciprocation assembly.
It is another object of the present invention to simplify the maintenance of the guide assembly.
It is yet another object of the present invention to reduce down time for maintenance of the guide assembly.
To achieve the foregoing in other objects in accordance with the present invention, a can body making apparatus that includes a frame, a contact member and a reciprocation assembly. The reciprocation assembly comprises a ram mounted for reciprocation relative to the frame and a guide assembly adapted to guide the ram for reciprocation relative to the frame. The contact member is for dynamically interfacing with at least a surface of the reciprocation assembly. The contact member also comprises a material capable of withstanding a minimum PV value of 50,000 psi*ft/min without lubrication.
To achieve further objects in accordance with the present invention, a reciprocation apparatus is provided that includes a frame, a contact member and a reciprocation assembly. The reciprocation assembly includes an elongated member adapted to reciprocate relative to the frame and a guide assembly adapted to guide the elongated member. The guide assembly includes a main body portion and a removable cartridge. The cartridge houses the contact member and is adapted to secure the contact member relative to the guide assembly. The contact member is for dynamically interfacing with at least a surface of the reciprocation assembly. In addition, the contact member and cartridge are adapted for common insertion and removal relative to the main body portion of the guide assembly.
To achieve still further objects in accordance with the present invention a can body making apparatus is provided. The apparatus includes a frame, a ram supported relative to the frame, and a drive assembly adapted to linearly reciprocate the ram relative to the frame. The apparatus further includes a can holding mechanism for holding a can blank, a die pack, a contact member and a guide assembly adapted to guide the ram. The guide assembly includes a main body portion and a cartridge removably attached to the main body portion. The contact member is disposed in and restrained by the cartridge and the contact member and cartridge are adapted for common insertion and removal relative to the main body portion of the guide assembly.
Still other advantages and objects of the present invention will become apparent to those skilled in the art from the following description wherein there are shown and described alternative exemplary embodiments of this invention. These exemplary advantages and objects are provided only as illustrative examples, and in no way are intended, nor should they be interpreted, as limiting or the only advantages or objects. As will be realized, the invention is capable of other different, obvious aspects, objects and embodiments, all without departing from the scope of the invention. These other objects, aspects and embodiments will be understood by those skilled in the art based upon the description and teachings herein. Accordingly, the drawings, objects and descriptions should be regarded as illustrative and exemplary in nature only, and not as restrictive.